A camera, such as a video camera used in a physical security system, may have the ability to operate in a “day mode” and a “night mode”. When in day mode, an infrared cut-off filter (“IR cut filter”) filters out infrared light from the light that is incident on the camera's imager; this results in the camera generating an image only from visible light. When visible light levels are low, the camera may be switched to night mode, which removes the IR cut filter from the path of the incident light. Consequently, the camera's imager is exposed to infrared light and to the remaining low levels of visible light. This facilitates generation of an infrared-light based image in conditions in which visible light levels may be insufficient to permit a good quality image to be generated.
Given the commercial benefits and flexibility of having a camera that is able to operate in day and night modes, research and development continue into methods, systems, and techniques for facilitating infrared imaging.